Organic silicon compounds such as organoalkoxysilanes, organochlorosilanes, or the like having organic groups and alkoxy groups bonded to silicon atoms or having chlorine-bonded silicon atoms are used widely for various types of industrial applications such as electronic materials, construction materials, or the like. A previously known method of producing organic silicon compounds (such as organoalkoxysilanes, organochlorosilanes, or the like) performs synthesis by causing reaction between a reactive organosilane as a raw material (i.e., alkoxysilanes, chlorosilanes, or the like) and a corresponding Grignard reagent in the presence of an ether type solvent such as diethyl ether or tetrahydrofuran. Rather than just diorganodialkoxysilanes, this method is widely used as a method for synthesis of general organoalkoxysilanes. Moreover, a method is known for the production of a phenyl-containing organosilicon intermediate using a phenyl Grignard reagent as a method of producing a phenyl-containing organosilicon intermediate for introduction of an aryl group such as the phenyl group.
For example, although a large amount of ether type solvent (diethyl ether, tetrahydrofuran, or the like) is generally used in order to increase stability of the Grignard reagent, such ether type solvents will readily be oxidized due to atmospheric oxygen to generate peroxides, and the safe handling of such solvents is difficult. Reduction of the utilized amount of ether type solvent is desired even in a large volume industrial production process, and the use of a large amount of ether type solvent has been a problem from the standpoint of safety.
Next, the aforementioned reaction between the Grignard reagent and the reactive silane compound is performed through two reaction steps, i.e. a step (first reaction vessel) for preparation of the Grignard reagent and a step (second reaction vessel) for reaction of the aforementioned Grignard reagent and the organosilane. There have thus been problems in that multiple reaction facilities are required, the time required for synthesis is prolonged, the return rate on reaction (production) facility resources declines, and running costs increase.
Moreover, the conventional generally used production method prepared the Grignard reagent beforehand in the first reaction vessel, transferred the Grignard reagent from the first reaction vessel to the second reaction vessel, and reacted the Grignard reaction with the organosilane. The target organic silicon compound was produced by trickling addition of the organosiloxane to the Grignard reagent to cause reaction between the organosilane and Grignard reagent.
However, when the Grignard reaction is prepared beforehand, the Grignard reagent prepared in the first reaction vessel is unstable. Since the Grignard reagent reacts with moisture and generates heat, the large volume preparation, storage, and liquid transfer of a Grignard reagent have been problematic from the standpoint of safety.
On the other hand, if the reaction is advanced by trickling addition of the organosilane into the Grignard reagent within a solvent such as ether or the like, the reaction occurs by trickling addition of a small amount of organosilane to an excess of Grignard reagent. Thus selectivity of the reaction is lowered, and byproducts thus become readily generated. As a result, the resultant generated product is a mixture of compounds corresponding to values of 0, 1, 2, 3, and 4 for m+n in the compound indicated in the following compounds of General Formula (3). Thus there has been a problem in that the yield of the target organosilane compound decreases.
In addition, after the coupling reaction between the Grignard reagent and the organosilanes, there is a need for removal of the byproduct magnesium salt by centrifugal separation or filtration. However, the salt obtained by separation by filtration includes a large amount of the ether type solvent, and such processing has been accompanied by the danger of exposure of workers to ether type solvent during disposal of the byproduct salt or the like. Although the ether type solvent remaining in the filtrate liquid after filtration may be separated from the target substance by distillation or the like, due to poor stability in the aforementioned manner, this has been accompanied by danger of explosion or fire when the ether based solvent is recycled or discarded. Furthermore, the byproduct salt that is generated when a Grignard reagent is used has high solubility in the ether type solvent. Thus when the ether solvent is removed from the filtrate liquid, there have been problems in that the dissolved byproduct salt precipitates out within the solution of the target substance, separation operations must be performed several times, and productivity and yield of the target organic silicon compound decline.